Hot melt adhesives containing silane compounds

ABSTRACT

Hot melt adhesive compositions characterized by their improved adhesion under conditions of high humidity or moisture; said adhesives comprising a blend of a synthetic polymer base and a specified silane compound.

United States Patent Flanagan et al.

[ Feb. 22, 1972 [54] HOT MELT ADHESIVES CONTAINING SILANE COMPOUNDS [72]Inventors: Thomas P. Flanagan, Green Brook; Irving Kaye, Murray Hill,both of NJ.

National Starch and Chemical Corporation, New York, NY.

221 Filed: June 25,1969

21] Appl.No.: 836,642

[73] Assignee:

[56] References Cited UNITED STATES PATENTS 2,898,313 8/1959 Ericks..106/163 3,045,036 7/1962 Jexetal ..260/824 3,492,372 1/1970 Flanagan..260/27 FOREIGN PATENTS OR APPLICATIONS 1,019,851 2/1966 Great BritainOTHER PUBLICATIONS Dow Corning Silane Coupling Agents 1967, pp. 8 to 24relied on Primary ExaminerI-losea E. Taylor Assistant Examiner-WilliamE. Parker Attorney-Thomas B. Graham [57] ABSTRACT Hot melt adhesivecompositions characterized by their improved adhesion under conditionsof high humidity or moisture; said adhesives comprising a blend of asynthetic polymer base and a specified silane compound.

5 Claims, No Drawings HOT MELT ADHESIVES CONTAINING SILANE COMPOUNDSBACKGROUND OF THE INVENTION Hot melt adhesives are solid combinations offilm forming resins, tackifying resins, rubbery polymers, plasticizers,waxes and similar materials which may be added to the composition inorder to impart various desired properties. Adhesive bonds derived fromhot melts are particularly useful because of their tackiness in themolten state and the speed with which they form strong bonds.

Hot melt adhesives are bonding agents which achieve a solid state andresultant strength by cooling as contrasted with other adhesives, suchas resin emulsion or lacquer adhesives, which achieve the solid statethrough evaporation or removal of solvents. A hot melt is athermoplastic material which is in the form of a 100 percent, by weight,solid. Application of heat melts the solid hot melt and brings it to theliquid state and, after removal of heat, it sets by simple cooling. Thelatter behavior is in direct contrast to thermosetting adhesives whichset or harden by the application of heat and which remain hard uponcontinued application of heat.

One of the disadvantages inherent in most hot melt adhesives is the factthat they are somewhat limited with regard to their use in adheringvarious substrates to the surfaces of glass containers since, underconditions of high humidity or dampness, the adhesive bonds obtainedwith hot melts will often deteriorate to a significant degree.Accordingly, since bottles, jars and other glass containers will oftenbe stored or used under conditions wherein they are exposed to a highhumidity or to substantial amounts of moisture, the use of mostcommercially available hot melts under such conditions has led tounsatisfactory results. One attempt to overcome this problem did succeedin providing a humidity resistant hot melt. However, it was based upon ahighly reactive system and, as a result, it displayed extremely poorheat stability.

Thus, it is the prime object of this invention to provide not meltadhesive compositions which display outstanding resistance to conditionsof high humidity and moisture without detracting from any of the otherproperties which are ordinarily necessary in such adhesives. A furtherobject of this invention is to provide hot melt adhesives which areparticularly suited for the bonding of various substrates to the surfaceof glass containers. Various other objects and advantages of thisinvention will be apparent to the practitioner from the followingdescription thereof.

TECHNICAL DISCLOSURE OF THE INVENTION We have now discovered that it ispossible to prepare hot melt adhesive compositions whose use results inthe formation of adhesive bonds characterized by their outstandingresistance to conditions of high humidity and moisture by blending asynthetic polymer adhesive base, as set forth hereinbelow, with aspecified silane compound.

The silane compounds whose presence is necessary in the novel adhesivesof this invention may be selected from the group of silane compoundsconsisting of:

wherein R is a group selected from the class consisting of the vinyli.e., ethenyl; gamma-methacryloxypropyl; beta-(3,4- epoxycyclohexyl);mercaptopropyl; gamma-glycidoxypropyl; gamma-aminopropyl;N-bis(beta-hydroxyethyl) gammaaminopropyl;N-beta-(aminoethyl)-gamma-aminopropyl; amyl; ethyl; phenyl; and, methylgroups; and, X is a group which can hydrolyze to yield a hydroxyl groupand which is selected from the class consisting of the chloro; ethoxy;acetoxy; beta-methoxyethoxy; and methoxy groups.

Specific examples of silane compounds corresponding to formula I,hereinabove, are vinyltrichlorosilane; vinyltriethoxysilane;vinyl-tris(beta-methoxyethoxy)silane;gammamethacryloxypropyltrimethoxysilane; beta-( 3,4-epoxycyclohexyl)-ethyltrimethoxysilane;gamma-glycidoxypropyltrimethoxysilane; gamma-aminopropyltriethoxysilane;N- bis(beta-hydroxyethyl)gamma-aminopropyltriethoxysilane;N-beta-(aminoethyl)-gamma-aminopropyltrimethoxysilane;ethyltriethoxysilane; amyltriethoxysilane; ethyltrichlorosilane;amyltrichlorosilane; phenyltrichlorosilane; phenyltriethoxysilane;methyltrichlorosilane; methyltriethoxysilane; vinyltriacetoxysilane;and, gamma-mercaptopropyltrimethoxy silane.

A specific example of a silane compound corresponding to formula II,hereinabove, is dimethyltriphenyltrimethoxytrisiloxane.

The synthetic polymer which comprises the adhesive base for our novelhot melt compositions may be selected from the group consisting of:

l. polyamides, i.e., the polymers resulting from the condensationbetween polyamines, such as hexamethylene diamine or ethylene diamine,with a polycarboxylic acid such as adipic acid, dimerized or polymerizedlinoleic acid, and sebacic acid; the latter polyamide resins having asoftening point, as determined by ASTM method E 28-5 8T, of from aboutto I25" C.;

2. polyolefins such as polyethylene and polypropylene; the latterpolyolefins having a molecular weight in the range of from about 1,500to 20,000;

3. cellulosic resins such as ethyl cellulsoe, cellulose acetate andcellulose acetate butyrate;

4. copolymers of ethylene and vinyl acetate which contain from about 4to 16 moles of ethylene per mole of vinyl acetate;

5. polyvinyl butyral;

6. polyvinyl methyl ether;

7. polyvinyl acetate and the random copolymers containing at least about40 percent, by weight, of vinyl acetate with one or more monomersselected from the group consisting of a. the alkyl esters of acrylic andmethacrylic acids, wherein said alkyl group contains from one to about10 carbon atoms, such, for example, as methyl acrylate, butyl acrylate,2-ethylhexyl acrylate, and the corresponding methacrylate esters;

b. anhydrides of ethylenically unsaturated dicarboxylic acids, such, forexample, as maleic anhydride; and,

c. the dialkyl esters of ethylenically unsaturated dicarboxylic acids,wherein said alkyl group contains from one to about eight carbon atoms,such, for example, as dibutyl maleate; and

8. homopolymers of the C C, alkyl esters of methacrylic acid such, forexample, as polymethylmethacrylate, and the random copolymers of two ormore of the latter C C alkyl esters of methacrylic acid with one anothersuch, for example, as the copolymer of n-butyl and isobutylmethacrylate.

The procedure for preparing these novel hot melt adhesive compositionsinvolves placing the adhesive base and any optional tackifiers ordiluents, as described below, in a steam or oil jacketed mixing kettleequipped with means for applying mechanical agitation. Thereupon, thetemperature should be raised to a range of from about to 350 F., theprecise temperature utilized depending upon the melting point of theadhesive base which is selected. When the adhesive base has melted,stirring is initiated and the silane compound is then added. Stirringand heating are continued until the silane compound is completelyincorporated into the molten adhesive base. The addition of water is tobe avoided since its presence would result in the premature hydrolysisof the silane compound.

The resulting hot melt adhesive composition can then be drawn off andmay be used immediately in hot pots in the manner to be describedhereinbelow. It may also be moltenextruded into rope form or convertedinto pellets, rods, cylinders, slugs or billets, or it may be granulatedor diced depending upon the equipment which will subsequently be used toapply the hot melt. As another alternative, the freshly preparedadhesive may be placed into cooling pans and held in bulk form for lateruse.

With regard to proportions, the hot melts of his invention shouldcontain at least about 0.1 percent, by weight, as based on the totalweight of the resulting composition, of one or more of theabove-described silane compounds in order to be able to demonstratetheir improved resistance to conditions of moisture and high humidity.It is not ordinarily advantageous to utilize more than about 5 percent,by weight, of one or more of these silane compounds in our novel hotmelts inasmuch as their use in higher concentrations does not appear tolead to any further improvements in their properties. Optimum resultshave been obtained with hot melts having a concentration of from about 2to 2.5 percent, by weight, of one or more silane compounds.

As a desirable optional ingredient, a diluent may be employed in ournovel systems, in a concentration of up to about 50 percent, by weight,of the total weight of the composition in order to reduce the meltviscosity or cohesive characteristics of the hot melt adhesivecomposition without appreciably decreasing its adhesive bindingcharacteristics. Among the applicable wax diluents are included: liquidpolybutene or polypropylene having a low molecular weight in the rangeof from about 700 to 1,200; petroleum waxes such, for example, asparaffin and microcrystalline waxes; polyethylene greases having amolecular weight of less than 1,000; hydrogenated animal, fish andvegetable fats; mineral oil; and, synthetic waxes such, for example, asFischer- Trop'sch wax.

Still another highly desirable class of optional additives which may beutilized in our novel hot melts are the so called tackifiers orplasticizers which serve to enhance the adhesion, soften, flexibilizeand introduce tack into the products of this invention. Suchplasticizers may be present in our compositions in a concentration of upto about 70%, by weight, as based on the total weight of thecomposition. They may be selected from the group consisting of:

1. natural and modified rosins such, for example, as gum rosin, woodrosin, tall-oil rosin, distilled rosin, hydrogenated rosin, dimerizedrosin, disproportionated and polymerized rosin; the term modified rosinsalso referring to esters of the above noted natural and modified rosinsincluding glycerol, methyl triethylene glycol and pentaerythritol estersof these rosins such, for example, as the glycerol ester of wood rosin,the glycerol ester of hydrogenated rosin, the triethylene glycol esterof hydrogenated wood rosin, the methyl ester of wood rosin and thepentaerythritol ester of polymerized rosin;

2. polyterpene resins having a softening point, as determined by ASTMmethod E 28-58T, of from about to 150 C.; the latter polyterpene resinsgenerally resulting from the polymerization of terpene hydrocarbons,such as the bicyclic mono-terpene known as pinene, in the presence ofFriedel- Crafts catalysts at moderately low temperatures;

3. cumarone-indene resins having a Ball and Ring softening point of fromabout 10 to 160 C.;

4. polystyrene and random copolymers of styrene in combination with atleast one different ethylenically unsaturated aromatic compound such,for example, as vinyl toluene and alpha-methyl styrene; the latter homoand copolymers having a Ball and Ring softening point of from about 55to 120 C.

5. petroleum derived aliphatichydrocarbon resins having a Ball and Ringsoftening point offrom about 80 to 120 C.; the latter resins resultingfrom the polymerization of monomers consisting primarily of olefins anddiolefms containing five carbon atoms therein;

6. phenolic-modified terpene resins such, for example, as the resinproduct resulting from the condensation, in an acidic medium, of abicyclic terpene and a phenol; the latter resins having a Ball and Ringsoftening point of from about to 160 C.;

7. chlorinated terphenyl and diphenyl resins containing from about 42 to65 percent, by weight, ofchlorine;

8. alkyl phthalate esters such, for example, as dibutyl and dioctylphthalate;

9. aryl phosphate esters such, for example, as tricresyl and triphenylphosphate;

10. aryl sulfonamide derivatives such, for example, as N- ethylpara-toluene sulfonamide, para-toluene sulfonamide and N-cyclohexylpara-toluene sulfonamide; and,

1 l. glycollate esters of phthalic acid such, for example, as butylphthalyl butyl glycollate; ethyl phthalyl ethyl clycollate and methylphthalyl ethyl glycollate.

Other optional additives may be incorporated into the hot meltcompositions of this invention in order to modify certain propertiesthereof. Among these additives may be included: stabilizers andantioxidants such, for example, as butylated hydroxytoluene, highmolecular weight hindered phenols, and substituted phosphites; colorantssuch as titanium dioxide and watchung red; and, fillers such as clay andtalc, etc.

The novel hot melts of this invention may be effectively utilized in avariety of packaging, laminating, carton sealing and book bindingoperations. Thus, they can be coated onto and used for the lamination ofvarious types of solid substrates including, for example, metallicfoils, paper, coated paper, corrugated board, paper board, cellophaneand polyolcfin films. However, as has been pointed out, hereinabove, ouradhesives display particular utility for adhering paper substrates, suchas labels and government tax stamps, to the surface of glass containerssuch as bottles and jars. The resulting adhesive bonds between the glassand the paper substrates are found to display outstanding resistance tothe conditions of high humidity and moisture to which such glasscontainers are often exposed.

The actual application of the hot melt compositions of this inventionmay be accomplished by the use of any conventional hot melt equipment.Ordinarily, the adhesive is first premelted at a temperature of about to300 F. whereupon it is placed into an applicator pot which is at atemperature of about 200 to 350 F. An applicator roll or extrusion tubecan then be used to apply either an overall coating or a patterned stripofthe adhesive to any desired substrate; the latter coating should havea final dry thickness of from about 0.5 to 4.0 mils. The thus coatedsubstrate should then be immediately applied or transferred to thesurface of the substrate upon which it is to be adhered. If the lattersubstrate is one having an irregular shape or surface, a compressionpad, wiping brush or rolls may be passed over the external face of theadhesive coated substrate so as to conform its shape to that of thesurface upon which it has been applied. As the adhesive coating coolsdown to room temperature, the bonding process will be completed.

The following examples will further illustrate the embodiment of thisinvention. In these examples all parts given are by weight unlessotherwise noted.

EXAMPLE I This example illustrates the use of a variety of silanecompounds and synthetic polymer bases in the preparation of a number ofdifferent formulations typical of the novel hot melt adhesives of thisinvention. Also included is a comparison of certain properties of theseadhesive formulations with products which were identical in theircomposition and method of preparation with the exception that they didnot, however, contain a silane compound component.

All of the adhesive formulations which are described in the followingtable were prepared by means of a procedure in which the specifiedsynthetic polymer adhesive base was first introduced into an oiljacketed, stainless steel kettle equipped with means for applyingmechanical agitation and which was being maintained at a temperature ofabout 300 F. Under agitation, the adhesive base was completely meltedand, at this point any diluents and/or tackifiers were added.

Next, the silane compound, where included in the formulation, was addedand agitation was then continued until it was completely admixed withthe molten adhesive base. The resulting formulation was then maintained,under agitation, at a temperature of about 225" F. Each of the thusprepared formulation, while still at a temperature of about 225 F., wasthen applied to one complete surface of each of three samples ofa/z-in::h by 5-inch strip oflabel stock so as to provide a film having afinal dry thickness of3 mils (l mil=0.00l inch). The thus-coated labelswere then immediately applied to the surface of an 8-ounce glass bottle.

A number of different testing procedures were then used to evaluate theadhesive bonds of the thus labeled bottles. The first of these testsevaluated their initial adhesion upon cooling to room temperature. Thistest involved an attempt to remove or delaminate the label from thebottle by picking it off with the fingers. As is seen in table I whichreports on the results of this test, delamination was not possible withany of the specimens, including those in which the adhesive did notcontain a silane compound, as was indicated by a tearing of the paperlabel upon its attempted removal from the bottle, i.e., in each case atearing bond had been developed.

In the so called iceproofness test, a specimen of each of the labeledbottles was completely immersed in water which was at at temperature of35 F. Each bottle was then examined after an interval of 3 hours andagain after an interval of 4 days. At these examinations, it was notedwhether:

l. the label was still strongly adhered to the bottle as evidenced bythe existence of tearing bond;

2. the label could be readily peeled off from the bottle withoutoffering any resistance so as to leave the glass surface clean andwithout any transfer of adhesive; or,

3. the label had voluntarily delaminated from the bottle. The results ofthis test are also included in table I in which the term tearingdesignates a tearing bond, the term weak is applied to a bond whichpermitted the label to be readily peeled off and "delaminated indicatesthat the label had voluntarily delaminated. The latter designations arealso used, in the table, to indicate the results of the humidityresistance test as described below.

The humidity resistance of each adhesive formulation was evaluated byplacing a specimen of each of the labeled bottles in a cabinet having acontrolled relative humidity of 95 percent and a temperature of 72 F.Each bottle was then examined at intervals of 24, 48 and 72 hourswhereupon it was noted whether:

1. the label was still strongly adhered to the bottle as evidenced by atearing bond; or,

2. whether the label could be readily peeled off without offering anyresistance so as to leave the glass surface clean and without anytransfer of adhesive. The results of this test are also included intable I, herein-below.

in the various formulations set forth below the different silanecompounds which were utilized are identified as follows:

No. l Amyltriethoxysilane No. 2 Vinyltriacetoxysilane No. 3N-beta-(aminoethyl)-gamma-aminopropyltrimethoxysilane No.4Dimethyltriphenyltrimethoxytrisiloxane No. 5 Phenyltriethoxysilane No. 6Phenyltrimethoxysilane No. 7 Gamma-glycidoxypropyltrimethoxysilane No. 8Phenyltrichlorosilane.

The composition, in parts by weight, of the various adhesiveformulations which were prepared is set forth hereinbelow. It is to benoted that those formulations designated by a number and a lettercontained a silane compound while those formulations designated by anumber alone were controls which did not contain a silane compound.

Formulatlon No. I No it.

Ethylenezvinyl acetate (8:1) copolymer 20 20 Gum rosin 65 65 Paraffin l0l0 Mineral oil 5 5 Silane No. l 2.5

No. 2 No. 20

Polyamide resin resulting from condensation of ethylene diamine andlinoleic acid dimer, said resin having a softening point of about l00 C.40 40 Glycerol ester of wood rosin 27 27 N-ethyl para-toluenesulfonamide 33 J3 Silane No. 5 2.5

No. 3 No. 3n

Polyethylene having a molecular weight of about 2,000 50 50 Polyterpeneresin having a softening point of about l [5 C. 35 35 Liquid polybutenehaving a molecular weight ofabout 600 l5 l5 Silane No.8 2.5

Number 4 4a 4b 4c 4d 4e 4f Ethylenezvinyl acetate (8:1)

copolymer 20 20 20 20 20 20 Gum rosin.-- 65 65 65 65 65 65 65 Paraflin.10 1O 10 10 10 Mineral oil. 5 5 5 5 5 Silane #2 2. 0 1.0 0. 1 Silane #3.2. 5 Sllane #4. 2. 0

P V '7 A 7 D No. 5 No. 51:

Ethyl cellulose l0 l0 Polymerized resin 45 45 Methyl ester of wood rosin45 45 Silane No. 5 2.5

No. 6 No. fin

Polypropylene 75 75 Petroleum derived aliphatic hydrocarbon resin,

softening point about 100 C. 25 25 Silane No. 5 2.5

No. 7 No. 711

Ethylenewinyl acetate (8zl copolymer 30 30 Hydrogenated rosin 70 70Silane No.6 2.0

No. 8 No.

Polyvinyl butyral l0 l0 Methyl ester of wood rosin 40 40 Glycerol esterof wood rosin 30 30 Hydrogenated castor oil 40 40 Silane No.5 2.5

No. 9 No. 911

Polyvinyl methyl ether 20 20 Gum rosin 55 55 Triethylene glycol ester ofwood rosin l5 l5 Hydrogenated castor oil l0 l0 Silane No.5 2.5

No. It) No. 1011 Ethylenezviriyl acetate (82] copolymer 20 20 Analpha-pinene derived polyterpene resin, softening point about I 15 C. 2020 Mineral oil 20 20 Paraffin 40 40 Silane No. 7 2.0

No. II No. l lu Pnlyvinyl acemle 65 65 Polyethylene having a molecularweight Chlorinated diphenyl resin having a of about IZOOQ 25 25 chlorinecontent of about 54%. by weight l l0 polywrpene resin having a fi iButyl phthalyl butyl glycollate 25 25 point f about 70 c 35 35 SilaneNo. S Polyethylene grease 45 45 Silane No. 6 2.0

No. l2 No. lZa

N0. [7 No. l7u

Polyamide resin resulting from condensation of 10 ethylene diamine andlinoleic acid dimer, softening Ethylenewinyl ucemte g; cupulymer 2Q Pabout 00 100 Glycerol ester of wood rosin no 60 s'lune 5 Fischer TropschWax l0 [0 Mineral oil l0 l0 NW 3 N04 '3 Silane No. 6 2.0

15 IN N x Ethylenezvinyl acetate (8:l copolymer l7.5 17.5 A 0 I Glycerolester of hydrogenated rosin 60 60 Mineral oil Ethylenezvinyl acetate(4.5:l) Paramn l0 l0 olyrner 2U 10 Silane NO- 5Styrenmalpha-methylstyrene copolymer.

2O softening point of about 75 C. 80 80 No. 14 No. 14a 5mm: 5

No. i) No. l9n

Vinyl acetate:2-ethyl hexyl acrylate i cnpolymerf d 50 25 Polyvinylacetate 60 clicewl u h) rogenue 50 so Terpene phenolic resin. softening"ri N 5 2 5 point ot'about l00 C. 20 20 sllme Tricresyl phosphate 20 20Silane No. 4 2.5

No. 15 No. 151! TABLE Iceprooiness test Humidity resistance testFormulation Initial N 0. bond 3h0lllS 4 days 24h0urs 48 hours 72 hours 1Tearing... Weak.--... Delam.... Weak.-.... Weak Weak.

.. Tearing... Tearing... Tearing... Tearing... Tearing. Weak Delarn....Weak Weak...... Weak. Tearing... Tearing... Tearing... Tearing...Tearing. Weak...... Delarn...- Weak Weak Weak.

Tearing... Tearing... Tearing... Tearing... Tearing.

eak...... Dela n.... Weak Weak Weak.

. Tearing... Tearing... Tearing... Tearing.

do D0. ..do....... Do. Partial Partial tearing. tearing. tearing.tearing. tearing. 4e ..do....... Tearing... Tearing... Tearing..Tearing. 4L. .-d0.. d (1 D0. 5... Delam. Weak. Weak. 5a. Tearing...Tearing.. Tearing. 6... Delam.... Weak. Weak. 6a- Tearing... Tearing...Tearing... Tearing. 7... Weak Delani.... Weak Weak Weak. 7a- Tearing.Tearing... Tearing. Tearing... Tearing.

ak Delani.... Weak Weak Weak.

Tearing... Tearing... Tearing... Tearing. Delain Weak...... Weak Weak.Tearing-.. Tearing... Tearing... Tearing. Deiarn.... Weak Weak......Weak. Tearing... Tearing... Tearing... Tearing. De1am.... Weak WeakWeak. Tearing... Tearing. Tearing... Tearing. Delam.... Weak Weak Weak.Tearing... Tearing. Tearing... Tearing. 13.. Delarn.... Weak. Weak Weak.

Tearing... Tearing. Tearing... Tearing. Delam.... Weak.-. Weak Weak.Tearing... Tearing. Tearing... Tearing. Dela mu" Weak. Weak...... Weak.Tearing... Tearing. Tearing... Tearing. Dela n.... Weak. Weak Weak.Tearing... Tearing- Tearing... Tearing. De1am.... Weak. Weak...... Weak.Tearing... Tearing. Tearing... Tearing. ak Delam.... Weak. Weak Weak.Tearing. Tearing... Tearing- Tearing... Tearing. 19.... ..do.. Weak..Delam.... Weak. Weak Weak. I 19a ..do Tearing... Tearing... Tearing...Tearing... Tearing.

P I h I h I O 40 The data presented in the above table is clearlyindicative of uyriuty met acryntc 4 mytmlcsmrhydmgcmucdmin 6O 60 thesubstantial improgement in resistance to conditions of high humidity andmoisture which is displayed by the novel Sum. NW 6 5 0 silane containinghot melt adhesives of this invention when the No. l6

None 75 latter products were compared, under identical conditions.

with comparable formulations which did not, however, contain thesesilane esters.

It is, thus, seen that this invention provides the practitioner What isclaimed is: 1. A hot melt adhesive composition consisting essentially ofa blend of (A) a synthetic thermoplastic polymer adhesive base selectedfrom the group consisting of polyamides resulting from the condensationreaction of polyamines and polycarboxylic acids; polyolefins; cellulosicesters and ethers; copolymers and ethylene and vinyl acetate whichcontain from 4 to 16 moles of ethylene per mole of vinyl acetate;polyvinyl butyral; polyvinyl methyl ether; polyvinyl acetate and therandom copolymers containing at least about 40 percent, by weight, ofvinyl acetate with one or more monomers selected from the groupconsisting of the C,-C alkyl esters of acrylic and methacrylic acids,anhydrides of ethylenically unsaturated dicarboxylic acids, the dialkylesters of ethylenically unsaturated dicarboxylic acids, wherein thealkyl group thereof contains from one to eight carbon atoms;homopolymers of the C -C alkyl esters of methacrylic acid and the randomcopolymers of two or more ofthe latter esters with one another; and (B)a silane compound corresponding to the formulas l n-srwxn andx-sio-si-0-si-X out at 011;

wherein R is a group selected from the class consisting of the ethenyl;garnma-methacryloxypropyl; beta-(3,4-epoxycyclohexyl); mercaptopropyl;gamma-glycidoxypropyl; gamma-aminopropyl; N-bis(beta-hydroxyethyl)gammaaminopropyl; N-beta-(aminoethyl)-gamma-aminopropyl; amyl; ethyl;phenyl; and, methyl groups, and X is a group which can hydrolyze toyield a hydroxyl group and which is selected from the class consistingof the chloro; ethoxy; acetoxy; beta-methoxyethoxy; and methoxy groups.

2. The hot melt adhesive composition of claim 1, wherein said silanecompound is present therein in a concentration of at least about 0.1percent, by weight, of the total weight of said composition.

3. The hot melt adhesive composition of claim 1, wherein a diluent isalso present therein in a concentration of up to about 50 percent, byweight, of the total weight of said composition, said diluent beingselected from the group consisting of liquid polybutenes andpolypropylenes having a molecular weight in the range of from about 700to 1,200; petroleum waxes; polyethylene greases having a molecularweight of less than 1,000; hydrogenated animal, fish and vegetable fats;mineral oil; and Fischer-Tropsch wax.

4. The hot melt adhesive composition of claim 1, wherein a tackifier isalso present therein in a concentration of up to about 70 percent, byweight, of the total weight of said composition, said tackifier beingselected from the group consisting of natural and modified rosins;polyterpene resins having a softening point offrom about 10 to 150 C.;cumarone indene resins having a Ball and Ring softening point of fromabout 10 to 160 C.; polystyrene and random copolymers of styrene with atleast one different ethylenically unsaturated aromatic monomer;petroleum derived aliphatic hydrocarbon resins having a Ball and Ringsoftening point of from about to C,; phenolic-modified terpene resinshaving a Ball and Rind softening point of from about 90 to C.;chlorinated terphenyl and diphenyl resins containing from about 42 to 65percent, by weight of chlorine; alkyl phthalate esters; aryl phosphateesters; aryl sulfonamide derivatives; and, glycollate esters of phthalicacid.

5. A hot melt adhesive composition comprising a blend of 17.5 parts ofan ethylenezvinyl acetate copolymer, 60 parts of the glycerol ester ofhydrogenated rosin, 12.5 parts of mineral oil, 10 parts of paraffin and2.5 parts of phenyltriethoxysilane; all of the latter proportions beingon a weight basis.

2. The hot melt adhesive composition of claim 1, wherein said silanecompound is present therein in a concentration of at least about 0.1percent, by weight, of the total weight of said composition.
 3. The hotmelt adhesive composition of claim 1, wherein a diluent is also presenttherein in a concentration of up to about 50 percent, by weight, of thetotal weight of said composition, said diluent being selected from thegroup consisting of liquid polybutenes and polypropylenes having amolecular weight in the range of from about 700 to 1,200; petroleumwaxes; polyethylene greases having a molecular weight of less than1,000; hydrogenated animal, fish and vegetable fats; mineral oil; andFischer-Tropsch wax.
 4. The hot melt adhesive composition of claim 1,wherein a tackifier is also present therein in a concentration of up toabout 70 percent, by weight, of the total weight of said composition,said tackifier being selected from the group consisting of natural andmodified rosins; polyterpene resins having a softening point of fromabout 10* to 150* C.; cumarone indene resins having a Ball and Ringsoftening point of from about 10* to 160* C.; polystyrene and randomcopolymers of styrene with at least one different ethylenicallyunsaturated aromatic monomer; petroleum derived aliphatic hydrocarbonresins having a Ball and Ring softening point of from about 80* to 120*C.; phenolic-modified terpene resins having a Ball and Rind softeningpoint of from about 90* to 160* C.; chlorinated terphenyl and diphenylresins containing from about 42 to 65 percent, by weight of chlorine;alkyl phthalate esters; aryl phosphate esters; aryl sulfonamidederivatives; and, glycollate esters of phthalic acid.
 5. A hot meltadhesive composition comprising a blend of 17.5 parts of anethylene:vinyl acetate copolymer, 60 parts of the glycerol ester ofhydrogenated rosin, 12.5 parts of mineral oil, 10 parts of paraffin and2.5 parts of phenyltriethoxysilane; all of the latter proportions beingon a weight basis.